Is the toolchains mechanism also exposed via the TAPI, so I could use it to bootstrap a JDK programmatically?

Well, you can inject an init script, can't you? So anything you want should be possible.

Right, but I was thinking about a more streamlines code only approach... as a possible alternative to https://github.com/foojayio/discoclient, which only seems to be semi-well maintained.

I'm which way is an init script not code?

It's not (pure) code in the sense that from the app that uses the TAPI I'd need to write out the init script as a temporary file in order to inject it into the build. I'm doing that already for other purposes, but for bootstrapping a specific Java version a pure API approach would have been nicer, IMO.

Well, you also write out a build that you then drive with the TAPI, don't you? So you are writing out files anyway, don't you? You can directly create that build you drive via TAPI as you need it for the provisioning.

Well, you also write out a build that you then drive with the TAPI, don't you?

Actually, no. I'm analyzing an external project that's "already there".

And it already configures JVM toolchain with auto-provisioning?

That varies. But In the vasty majority of cases, no.

I might remember wrongly, but as far as I know, if you need to modify the build that you drive, you have to inject an init script.